Liquid dispensing apparatus



Filed March 5, 1962 J as r/N J .S/MP/RO BY FIELl ArTaRA/E Y United States Patent 3,143,252 LIQUE DISPENSING APPARATUS Justin J. Shapiro, 39 Domingo Ave., Berkeley, Califa Filed Mar. 5, 1962, Ser. No. 177,294 12 Claims. (Cl. 222-309) This invention relates to liquid dispensing devices, and more particularly to manually operated burette devices for dispensing accurately measured volumes of liquids, such as chemical reagents, or the like.

A main object of the invention is to provide a novel and improved dispensing burette device of the plunger type, said device being relatively simple in construction, being easy to operate, and being extremely useful for repetitively dispensing accurately measured amounts of liquid, for example, for delivering measured amounts of liquid from a reagent bottle to receiving vessels such as test tubes, or the like.

A further object of the invention is to provide an improved dispensing burette device which is easy to adjust for dispensing a desired volume of liquid, which is relatively durable in construction, which involves relatively few parts, and which is inexpensive to manufacture.

A still further object of the invention is to provide an improved dispensing burette which is compact in size, which is highly accurate, which can be inverted without leakage of liquid therefrom, whereby air can be easily removed from the system with which it is employed, and which can be completely filled without the inclusion of air bubbles.

A still further object of the invention is to provide an improved dispensing burette device which can be refilled without the necessity of priming same, and which may be easily transferred from one liquid reservoir to another.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a fragmentary elevational view, partly in vertical cross-section, of an improved dispensing burette constructed in accordance with the present invention, shown installed in a typical reagent bottle.

FIGURE 2 is a plan view taken substantially on the line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged horizontal cross-sectional view taken on the line 33 of FIGURE 1.

FIGURE 4 is an enlarged horizontal cross-sectional view taken on the line 44 of FIGURE 1.

FIGURE 5 is a fragmentary elevational view of a modified form of adjustable stop means for the dispensing plunger of the burette.

Referring to the drawings, 11 generally designates an improved dispensing burette device according to this invention, shown installed in a reagent bottle 12 of generally conventional construction, the bottle 12 being supported on a moulded plastic base 13 which is integrally formed with an upstanding annular corrugation 14 of substantial height defining a circular seat 15 shaped to closely receive the bottom of the bottle and to support same against tipping. The base 13 is formed with a wide flange 16 extending outwardly from the upstanding corrugation 14.

The burette device 11 comprises a tubular main barrel or syringe chamber 17 of transparent material, such as glass, or the like. The barrel is adapted to engage through a central aperture 21 in the top wall 21 of a downwardly flaring sealing cap 19 provided on the bottle 12. Barrel 17 is integrally formed with an annular rib 18. Aperture 21 is of sufricient size to pass said rib 18. The cap is integrally formed with internal threads 22 which are threadedly engageable with external threads 23 on the neck 24 of bottle 12. Respective O-rings 25 Ice and 26 of resilient deformable material surround the barrel 17 above and below the rib 18 and are sealingly compressed against the rib by top wall 20 when the cap 19 is tightened, the upper O-ring being compressed between top wall 20 and rib 18 and the lower O-ring 26 being compressed between rib 18 and the top rim of neck 24.

The upper O-ring 25 may be split to facilitate its installation around the barrel above rib 18 when the device is assembled.

A dispensing plunger 27 is slidably and sealingly disposed in the upper portion of barrel 17, being provided at its top end with an operating knob or flange 28 of suitable shape, for example, of square shape, as shown. The top surface of operating flange 28 is formed with a spherical depression or recess 29, defining a finger-receiving recess or cavity for exerting downward force on plunger 27, said cavity being axially aligned with the plunger 27.

The top end of barrel 17 is integrally formed with an outwardly projecting annular head or flange 30. A depending rod member 31 is rigidly secured to an outer corner portion of the flange 28 and extends parallel to barrel 17. An adjustable stop collar 32 is slidably mounted on the rod member 31, being provided with a clamping screw 33 which is clampingly engageable with rod member 31 to lock the stop collar 32 in adjusted position thereon. Collar 32 is engageable with stop flange 343 to limit the retraction of plunger 27 upwardly in barrel 17, and to thus establish the amount of liquid which will be drawn into the barrel.

As an alternative, as shown in FIGURE 5, the stop collar, shown at 32 may be threaded on the rod, shown at 31 and the rod may be provided with a locknut 33'.

The rod 31 may be provided with longitudinally spaced indentations 51 adapted to receive the tapered tip of set screw 33 at settings of stop collar 32 corresponding to predetermined delivery volumes, thereby providing a rapid means of fixing the collar 32 to deliver specific volumes, as required.

An enlarged head 34 is provided on the bottom end of rod member 31 to prevent loss of the stop collar 32 when clamping screw 33 is loosened.

A stop lug 35 is integrally formed in the barrel 17, said stop lug 35 being engageable with the bottom end of plunger 27 to limit its downward movement. The external surface of the barrel is inscribed with a volume scale 36 whose zero point is at the level of the top end of stop lug 35, or may be at the level of an index line, provided on the bottom end of the plunger, when the plunger is engaged with the stop lug. Such an index line is shown at 50 in FIGURE 1.

Barrel 17 is integrally formed subjacent stop lug 35 with a depending tubular inner chamber 36 which communicates at its top end with an outwardly directed, downwardly and outwardly inclined delivery conduit 37 on which is secured a discharge tip 38 formed at its outer end with the depending delivery spout 39.

The lower portion of barrel 17 is formed with the frusto-conical downwardly tapering annular seat portion 40 which merges with a reduced intake conduit 41 of sufficient length to extend adjacent the bottom of the bottle 12. An upwardly movable valve ball 42 normally engages in the vertex portion of seat member 40, sealing 011 the conduit 41 but being free to rise responsive to suction developed when plunger 27 is moved upwardly. The tubular chamber 36 terminates adjacent the valve seat portion 40 and is provided with the bell-shaped open bottom end portion 43 adapted to receive the ball 42 when the burette device is inverted, as will be presently described.

The bell-shaped portion 43 is defined by the provision of an annular reduced neck portion 44 adjacent the bottom end of tubular chamber 36. The neck portion 44 is sufiiciently reduced in diameter to define a valve seat for the ball 42 on which said ball sealingly engages when the burette device is inverted, preventing liquid from bottle 12 from entering chamber 36 under these conditions.

As shown in FIGURE 1, the clearance between bellshaped portion 43 and the wall of barrel 17 is insufiicient to allow valve ball 42 to pass therebetween.

A second valve .ball 45 is provided in chamber 36 above neck portion 44, the ball 45 normally seating on said neck portion, but rising to allow liquid to be forced out of barrel 17 through chamber 36 and conduit 37 when plunger 27 is moved downwardly on its delivery stroke. Under these conditions, valve ball 42 is held seated in the vertex of valve seat portion 40 by the downward pressure of liquid thereagainst.

A cylindrical weighting glass rod 53 is loosely and slidably provided in chamber 36 immediately above ball 45, normally engaging same and adding the force of its weight to the ball and thus increasing its sealing efliciency. If so desired, the weighting rod 53 may be omitted.

Chamber 36 is integrally formed with an indentation 46 located a short distance above neck portion 44, to restrict the bore of chamber 36 at this location so as to prevent movement of rod 53 and ball 45 therepast. Thus, ball 45 is free to rise but is limited in its upward movement by the indentation 46. As shown in FIGURE 3, the indentation projects sufliciently into the bore of chamber 36 to prevent rod 53 and ball 45 from moving therepast, but does not impose any substantial restriction on the upward flow of liquid through said chamber.

When the burette is assembled with a bottle 12 containing reagent or other liquid to be dispensed, before dispensing the liquid it is first necessary to remove all the air from the burette in order to insure dispensing accuracy. To remove the air, the plunger 27 is fully elevated and cap 19 is then tightened. The assembly, including the bottle 12 and the burette 11 is then inverted, and the plunger is then pushed inwardly in the barrel 17, whereby to expel the air therefrom, the plunger being pushed inwardly to engage the stop member 35.

As above mentioned, when the apparatus is inverted the ball 42 drops into the bell-shaped member 43, sealing the chamber 36 and preventing the liquid from flowing out of the dispensing tip 38.

The apparatus is then returned to its upright position, and the cap 19 is then loosened sufficiently to allow air to enter bottle 12 to replace liquid as it is dispensed. The desired volume to be dispensed for each stroke of the plunger is established by setting collar 32 so that it engages the flange 30 When the bottom index mark 50 of the plunger is adjacent the desired volume on the scale 36'.

The desired predetermined volume of liquid may then be dispensed by merely alternately raising and lowering the plunger through its permissive range of movement.

Before dispensing, the chamber 36, conduit 37 and dispensing tip 38 should be completely filled with liquid to insure accuracy of the dispensed volumes of liquid.

While a specific embodiment of an improved liquid dispensing apparatus has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake member adjacent the end of the chamber opposite said actuating portion, a tapered seat member communicatively connecting said intake member to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable therein, a laterally extending discharge conduit on said syringe chamber, and an inner chamber in said syringe chamber communicatively connected to and extending downwardly a substantial distance from said discharge conduit, the lower end of said inner chamber extending adjacent said seat member and being formed with an inwardly convergent bell-shaped open lower end portion adapted to sealingly receive said valve ball when the device is inverted.

2. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, an inner chamber in said syringe chamber communicatively connected to and extending downwardly a substantial distance from said discharge conduit, the lower end of said inner chamber extending adjacent said frusto-conical seat member and being formed with an inwardly convergent bell-shaped open lower end portion adapted to sealingly receive said valve ball when the device is inverted, and a discharge tip on the outer end of said discharge conduit formed with a depending discharge spout.

3. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, and a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending downwardly a substantial distance from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member and being formed with an inwardly convergent open bellshaped portion adapted to sealingly receive said valve ball when the device is inverted.

4. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending downwardly a substantial distance from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member, and a restricted neck portion in the lower end of said inner chamber defining a bell-shaped portion having an internal valve seat adapted to receive said valve ball when the device is inverted.

5. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending downwardly a substantial distance from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member and being formed with a restricted neck portion defining a bellshaped lower end having an internal valve seat adapted to sealingly receive said valve ball when the device is inverted, a second valve ball in said inner chamber disposed above and sealingly engageable in the top of said restricted neck portion, and stop means in the lower portion of said inner chamber spaced downwardly a substantial distance from said discharge conduit and limiting movement of said second valve ball away from said restricted neck portion.

6. The structure of claim 5, and means to sealingly and releasably secure the syringe chamber substantially vertically in the neck portion of a liquid container.

7. The structure of claim 5, and an external peripheral sealing rib on the syringe chamber an annular cap engaged on the syringe chamber around the rib and adapted to be releasably secured on the neck portion of a bottle receiving the syringe chamber and resilient deformable sealing means between the cap and the sealing rib.

8. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending downwardly a substantial distance from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member and be ng formed with a restricted neck portion defining a bell-shaped lower end having an internal valve seat adapted to sealingly receive said valve ball when the device is inverted, a second valve ball in said inner chamber disposed above and sealingly engageable in the top of said restricted neck portion, and inwardly projecting stop means in said inner chamber spaced a substantial distance downwardly from said discharge conduit and limiting movement of said second valve ball away from said restricted neck portion.

9. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a de pending rod secured to said actuating portion and extending parallel to said syringe chamber, an outwardly projecting stop flange on said syringe chamber extending adjacent said rod, a stop collar adjustably mounted on said rod and being engageable with said flange to limit extension of said dispensing plunger, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit On said syringe chamber, a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending downwardly a substantial distance from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member and being formed with a restricted neck portion defining a bell-shaped lower end having an internal valve seat adapted to sealingly receive said valve ball when the device is inverted, a second valve ball in said inner chamber disposed above and sealingly engageable in the top of said restricted neck portion, and

an inwardly projecting indentation in said inner chamber spaced a substantial distance downwardly from said discharge conduit and limiting movement of said second valve ball away from said restricted neck portion.

10. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending a substantial distance downwardly from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member and being formed with a restricted neck portion defining a bell-shaped lower end having an internal valve seat adapted to sealingly receive said valve ball when the device is inverted, a second valve ball in said inner chamber disposed above and sealingly engageable in the top of said restricted neck portion, inwardly projecting stop means in said inner chamber spaced at substantal distance downwardly from said discharge conduit and limiting movement of said second valve ball away from said restricted neck portion, and a weighted member between said stop means and said second valve ball to exert a downward biasing force on said second valve ball.

11. The structure of claim 1G, and a discharge tip on the outer end of said discharge conduit formed with a depending discharge spout.

12. In a burette device of the character described, a syringe chamber, a dispensing plunger sealingly and slidably mounted in said chamber and being provided with an actuating portion projecting from the chamber, a depending rod secured to said actuating portion and extending parallel to said syringe chamber, an outwardly projecting stop flange on said syringe chamber extending adjacent said rod, a stop collar adjustably mounted on said rod and being engageable with said flange to limit extension of said dispensing plunger, a liquid intake conduit adjacent the end of the chamber opposite said actuating portion, a frusto-conical seat member communicatively connecting said intake conduit to said end of the chamber, a valve ball disposed in said seat member and being sealingly engageable in its vertex, a laterally extending discharge conduit on said syringe chamber, a substantially tubular inner chamber in said syringe chamber communicatively connected at one end to and extending downwardly a substantial distance from said discharge conduit, the other end of said inner chamber extending adjacent said frusto-conical seat member and being formed with a restricted neck portion defining a bell-shaped lower end having an internal valve seat adapted to sealingly receive said valve ball when the device is inverted, a second valve ball in said inner chamber disposed above and sealingly engageable in the top of said restricted neck portion, an inwardly projecting indentation in said inner chamber spaced a substantial distance downwardly from said discharge conduit and limiting movement of said second valve ball away from said restricted neck portion, and a rod-like weight member between said indentation and said second valve ball to exert a downward biasing force on said second valve ball.

References Cited in the file of this patent UNITED STATES PATENTS 2,690,278 Bocheller Sept. 28, 1954 2,792,157 Gilman May 14, 1957 2,911,921 Adams Nov. 10, 1959 

3. IN A BURETTE DEVICE OF THE CHARACTER DESCRIBED, A SYRINGE CHAMBER, A DISPENSING PLUNGER SEALINGLY AND SLIDABLY MOUNTED IN SAID CHAMBER AND BEING PROVIDED WITH AN ACTUATING PORTION PROJECTING FROM THE CHAMBER, A LIQUID INTAKE CONDUIT ADJACENT THE END OF THE CHAMBER OPPOSITE SAID ACTUATING PORTION, A FRUSTO-CONICAL SEAT MEMBER COMMUNICATIVELY CONNECTING SAID INTAKE CONDUIT TO SAID END OF THE CHAMBER, A VALVE BALL DISPOSED IN SAID SEAT MEMBER AND BEING SEALINGLY ENGAGEABLE IN ITS VERTEX, A LATERALLY EXTENDING DISCHARGE CONDUIT ON SAID SYRINGE CHAMBER, AND A SUBSTANTIALLY TUBULAR INNER CHAMBER IN SAID SYRINGE CHAMBER COMMUNICATIVELY CONNECTED AT ONE END TO AND EXTENDING DOWNWARDLY A SUBSTANTIAL DISTANCE FROM SAID DISCHARGE CONDUIT, THE OTHER END OF SAID INNER CHAMBER EXTENDING ADJACENT SAID FRUSTO-CONICAL SEAT MEMBER AND BEING FORMED WITH AN INWARDLY CONVERGENT OPEN BELLSHAPED PORTION ADAPTED TO SEALINGLY RECEIVE SAID VALVE BALL WHEN THE DEVICE IS INVERTED. 